Refrigerating apparatus



Sept], 1936. H. M. GRAHAM;

REFRIGERATING APPARATUS Filed Aug. 12, 1952 2 Sheets-Sheet 1 INVENTQR flarold M. Graham 3 5 ATTORNEYS md/ m/ Sept. 1, 1936.

H. M. GRAHAM REFRIGERATING APPARATUS.

Filed Aug. 12, 1932 2 Sheets-Sheet 2 INVENTOR Jidrold M. Graham ATTORNEYS Patented Sept. 1, 1936 PATENT OFFICE REFRIGERATING APPARATUS Harold M. Graham, Buffalo, N. Y., assignor, by mesne assignments, to Ross Heater & Mfg. Co. Inc., Buifalo, N. Y., a corporation of New York Application August 12,

19 Claims.

This invention relates to apparatus for lowering the temperatures of fluids such as are employed as circulating or refrigerating media. More particularly the invention is concerned with apparatus wherein the lowering of the temperature of the fluid is effected in stages by evaporation of a part of the fluid.

One object of the invention is to provide apparatus in which the relation between the rates of evaporation of the fluid in the various evaporating chambers is predetermined and is maintained under variable loads and operating conditions.

A further object is to provide apparatus wherein the rate of evaporation in all of the evaporating chambers is reduced when the temperature of the fluid in any one of the chambers falls below a predetermined value and is increased when the temperature of the fluid in any one of the said chambers rises above a predetermined value.

The invention is illustrated in the accompanying drawings, in which:

Figure 1 is a view in plan of apparatus embodying features of the invention.

Figure 2 is a vertical longitudinal section through the apparatus.

Figure 3 is an enlarged detail section of one of the control units taken along line 3-3 of Figure 1.-

The apparatus, as illustrated, includes an evaporator 5 in which the temperature of a fluid, for example, a refrigerating medium may be lowered to a predetermined value prior to its delivery to the cooling coils of the refrigerating system. Partitions 6, 1 and 8 divide the evaporator into a series of compartments 9, H), II and 12. A horizontal wall l3 which is arranged in the compartment 9 co-operates with the partition 6 to provide an evaporating chamber M. A similar wall I5 in the compartment l0 co-operates with the partitions 6 and I to provide a second evaporating chamber [6 while a third evaporating chamber I7 is provided in the compartment H by a horizontal wall l8 and the partitions 1 and 8. The compartment l2 provides a fourth evaporating chamber. The refrigerating medium is introduced into the evaporating chamber M from a pipe l9. From this chamber the refrigerating medium, owing to the stepped formation of the bottom walls of the evaporating chambers, is caused to flow by gravity successively through the said chambers to the chamber 12, the said medium being discharged from each chamber into the succeeding chamber through a conduit 20. The refrigerating medium is preferably introduced into each of the evaporating chambers in the form of a spray. To this end the various 1932, Serial No. 628,522

conduits may be suitably perforated. A predetermined volume of refrigerant is maintained in the apparatus by a float controlled valve 2| which is included in the supply line l9. The temperature of the refrigerating medium is lowered successively and to a predetermined degree in each of the evaporating chambers, the apparatus being so designed that the temperature of the refrigerant in the chamber I2 is lowered to and maintained at a predetermined value. frigerant may be withdrawn from the chamber l2 through a pipe 22 by a suitable pump 23, the latter being adapted to circulate the refrigerant through the cooling coils of the refrigerating sys- The re- 10 tern. In this connection it is to be understood, of 15 course, that the liquid which is introduced into the evaporating chamber It may be the liquid which is circulated through the cooling coils, or it may be a liquid which is obtained from an independent source.

The evaporating chamber lfl is in communication with the evaporating chamber l6 through an opening 24 which is formed in the partition 6, while the evaporating chamber I6 is in communication with the evaporating chamber I! through an opening 25 which is formed in the partition 1. The evaporating chamber l'l communicates with the evaporating chamber l2 through an opening 26 which is formed in the partition 8. Each opening is designed to permit the passage of so much vapor as is required to lower the temperature of the refrigerating medium in the chamber with which it is associated to a predetermined degree. fore, of each of the evaporating chambers is progressively larger, it being understood, of course, that the volume of vapor which must be removed from each chamber becomes greater as the temperatureto which the liquid is to be cooled becomes lower.

The refrigerating medium is lowered to the desired temperature by a series of ejectors 21, the suction ends of all of the ejectors being in communication with the evaporating chamber I 2. Steam is supplied to the ejectors through a supply line 29, the delivery of steam from the sup-.

The opening, there-- her 35, however, is connected by a pipe 3? to a compressed air line 38. Hence when compressed air is admitted into the air chamber 35, the diaphragm 33 is movable to hold the element iii of the valve open against the spring 35, the latter being adapted when the supply of compressed air is cut ofif to move the element iii to its closed po= sition.

In the operation of the apparatus the refrigcrating medium passes successively through the various evaporating chambers and that portion thereof which vaporizes passes by way of the various outlet openings to the chamber E2, the opening 24, in the embodiment illustrated, being of such a size that it will permit the passage of a quantity of vapor which is substantially equal to the capacity of one of the ejectors, the opening 25 being of such a size that it will permit the passage of an amount of vapor equal to the capacity of two of the ejectors while the opening 26 is of such a size that it will permit the passage of an amount of vapor equal to the capacity of three of the ejectors. The temperature of the refrigerating medium, therefore, is lowered successively in each of the evaporating chambers. For example, if the medium which is introduced into the chamber M is of a temperature of 60 F. and its final temperature is to be 40 F., then the apparatus may be so designed that the liquid will be cooled from 60 F. to 55 F. in chamber it, from 55 F. to 50 F. in chamber 86, from 50 F. to. 45 F. in chamber H and from 45 F. to 40 F. in the chamber l2.

Means is provided whereby one or more of the ejectors may be rendered inoperative in the event that the temperature of the refrigerating medium lowers in any of the evaporating chambers to a substantial degree below the value intended. To this end a valve control unit 39 is employed in connection with each of the valves 30. The said unit (Fig. 3) includes a body 40 in which a valve chamber 6! is formed. The chamber M provides a path of communication between the compressed air supply line 38 and the pipe 31 with which it is associated. A valve 42 which is arranged in the chamber 4| is provided with a stem 53. One end of an arm 44 which is pivotally mounted upon the body E of the unit is urged by a spring 45 in a direction which will seat the valve '42 and cut off communication between the pipes 37 and 33. intermediate its ends the arm 86 carries a pin 66 by which it is supported upon an expansible receptacle 41. The latter communicates with a tubular element 48 which is immersed in the refrigerating medium of the chamber with which the unit is associated, the said element and receptacle containing a suitable temperature responsive fluid.

The parts are so designed that when the temperature of the refrigerating medium is within the predetermined range intended the thermostatic fiuid through the agency of the receptacle 41 holds the free end of the arm 44 at the upward limit of its range of movement against the action of the spring 45. The compressed air, therefore, which is emitted through the pipe 38 forces the valve 42 oil its seat whereby the compressed air from the pipe 38 is admitted to the pipe 31 and hence the air chamber 35. The valve element 3|, therefore, is maintained open against the action of the spring 36 and steam is admitted to the nozzles of the ejector associated therewith. If, however, the temperature of the refrigerating medium lowers to a point substantially below the temperature intended the thermostatic fluid in the element 33 and the receptacle ii contracts and the free end of the arm it, under the influence of the spring 45, lowers to close the valve 52. Thereupon the supply of compressed air to the air chamber of the valve 30 is cut off and the spring 36 moves the element 3i of the valve to its closed position, thereby cutting off the supply of steam to the nozzles of the pjector associated therewith. When the temperature of the re-' frigerating medium raises to a value within the predetermined range the unit 39 is automatically operative to again permit steam to pass to the ejector. The element 55 may be adjusted relatively to the arm M, so that the control unit is operative to close the' valve 30 with which it is associated when the temperature of the refrigerating medium in which the element 43 is immersed lowers to a predetermined value, a hand 36a which is carried by the element 46 co-operat ing with a suitable dial 467) to indicate the temperature at which the unit is operative to close the said valve.

In accordance with the invention one of the units 39 is employed in connection with each of the evaporating chambers. Hence should the temperature of the refrigerating medium in any one of the chambers fall substantially below the predetermined value to which it is to be lowered in the chamber then the unit employed in connection with the said chamber is automatically operative to cut off the supply of steam to one or more of the ejectors. If the temperature of the refrigerating medium does not attain the piedetermined temperature desired the valve control units of the succeeding evaporating chamber will automatically cut off the supply of steam to one or more of the remaining ejectors. It will be apparent that relation between the rates of evaporation of the refrigerating medium in the various chambers is predetermined and that such relation will be maintained under varying load and operating conditions. Thus, when one of the ejectors is rendered inoperative, owing to the temperature of the refrigerating medium being below the desired value in one of the evaporating chambers, evaporation of the refrigerating medium is reduced in all of the evaporating chambers. In other words, the lowering in temperature of the refrigerating medium progresses at a predetermined rate as the said medium passes through the evaporating chambers and this despite variations in the load upon the apparatus. An advantage which is attained, therefore, is that the apparatus is capable of maintaining a large body of refrigerating medium at a predetermined temperature with a minimum consumption of steam. I

The ejectors 21 discharge into a condenser 49 which is divided by bafiles 50 into condensing chambers there being a condensing chamber for each of the ejectors. The uncondensed vapors are withdrawn from the various condensing chambers of the condenser by ejectors 52, there being one ejector for each of the condensing chambers and each of the ejectors being in communication with its respective condensing chamber by a pipe 53. Cooling water may be circulated through the tubes of the condenser through suitable inlet and outlet connections 54 and 55 respectively while the condensate from the various chambers may be conducted serially through the various condensing chambers by U-shaped connections 56. Each of the latter conducts condensate from one of thechambers to the adjacent chamber, the condensate from all of the chambers being discharged from the last chamber in the series through an outlet connection 51.

The steam from the ejectors 52 and the entrained vapors are discharged into a secondary condenser 58 in which a vacuum is maintained by an ejector 59. The latter discharges into an auxiliary condenser 60 which is in communication with'the atmosphere by way of a vent 6|. Condensate from the condenser 59 may be conducted by a pipe 62 to the condenser 49 and discharged therefrom through the outlet connection 51. The condenser construction described has the advantage that in the event that any of the ejectors is rendered inoperative, the efficiency of the remaining. ejectors is not impaired.

chambers so that said ejectors communicate in directly with the remainder of said chambers.

whereby a partial evaporation of the liquid is efiected .in each of said chambers by said ejectors and means for regulating said ejectors to lower the temperature of the said liquid to a predetermined value as it flows through the said chambers. r

2. In apparatus for cooling a liquid, the combination of a plurality of evaporating chambers through which the liquid is caused to flow, a plurality of steam ejectors communicating with one of said chambers, means providing a path of communication between said chambers whereby a partialevaporation of the liquid is effected in each of said chambers by said ejectors and means for rendering one of said ejectors inoperative when the temperature of the liquid in one of said chambers falls below a predetermined value.

3. In apparatus for cooling a liquid, the combination of. a' plurality of evaporating chambers through which the liquid is caused to flow, a plurality of steam ejectors communicating with one of said chambers, means for providing a path or communication between said chambers whereby a partial evaporation of the liquid is effected in each oi. said chambers by said ejectors and means for rendering said ejectors inoperative when the temperature of the liquid in said chambers falls below a predetermined value.

4. In apparatus for cooling a liquid, the comibination of a plurality of evaporating chambers through which the liquid is caused to flow, a plurality of steam ejectors communicating with one of saidphambers, means providing a path of communication between said chambers whereby a partial evaporation of the liquid is cifected in each of said chambers by said ejectors and means responsive to the temperature of the liquid in one of said chambers for rendering one of said ejectors inoperative when the temperature said liquid falls below a predetermined value.

5. In apparatus for cooling a liquid, the combination of a plurality of evaporating chambers through which the liquid is caused to flow. a plurality of steam ejectors communicating with one of said chambers, means for providing a path of communication between said chambers whereby a partial evaporation of the liquid is effectedin each of said chambers by said ejectors and means responsive to the temperature of the liquid in said chambers for rendering said ejectors inoperative when the temperature of the liquid falls below a predetermined value.

6. In apparatus for cooling a liquid, the combination of a plurality of evaporating chambers through which the liquid is caused to flow, exhausting means communicating with one of said chambers, means for providing a path of communication between said chambers whereby a partial evaporation of the liquid is efiected in each of said chambers by said exhausting means and means for reducing the rate of evaporation of the liquid in said chambers when the temperature of the liquid in one of said chambers falls below a predetermined value.

7. In apparatus for cooling a liquid, the combination of a plurality of evaporating chambers through which the liquid is caused to flow, exhausting means communicating with one of said chambers, means for providing a path of communication between said chambers whereby a partial evaporation of the liquid is effected in each of said chambers by said exhausting means and means responsive to the temperature of the liquid in one of said chambers for reducing the rate of evaporation of the liquid in said chambers when the temperature of the liquid in one of said chambers falls below a predetermined value.

8. In apparatus for cooling a liquid, the combination of a series of evaporating chambers through which the liquid is caused to flow, exhausting means communicating with one of said chambers and means providing a path of communication between each of said evaporating chambers and the'succeeding chamber in the series, whereby a partial evaporation of the liquid is efiected in each of said chambers by said exhausting means, the cross-sectional areas of the paths of communication between the various evaporating chambers being progressively larger, whereby the temperature of the liquid is progressively lowered as it passes through the said chambers.

9. In apparatus for cooling a liquid, the combination of a series of evaporating chambers through which the liquid is caused to flow, exhausting means communicating with one of said chambers, means providing a path of communication between each of said evaporating chambers and the succeeding chamber in said series, whereby a partial evaporation of the liquid is eitected in each of said chambers by said exhausting means, the cross-sectional areas of the paths of communication between the various evaporating chambers being progressively larger, whereby the temperature of the liquid is progressively lowered as it passes through the said chambers and means for reducing the rate of evaporation of the liquid in said chambers when the temperature of the liquid in one of said chambers falls below a predetermined value.

10. In apparatus for cooling 9. liquid, the combination of a receptable, a partition in said receptacle for dividing the latter into a plurality of evaporating chambers, means for causing the liquid to flow through said chambers in succession and a plurality of steam ejectors each of which communicates directly with one of said chambers, said partition being formed with an opening through which said ejectors communicate indirectly with a second of said chambers, whereby a partial evaporation of the liquid is eiiected in each of said chambers by said ejectors and means for regulating said ejectors to lower the temperature of the said liquid to a predeterceptacle for dividing the latter into a plurality of evaporating chambers, means for causing the liquid to flow through said chambers in succession, a plurality of steam ejectors communicating with one of said chambers, said partition being formed with an opening, whereby a partial evaporation of the liquid is effected in each of said chambers by said ejectors and means: for rendering one of said ejectors inoperative when the temperature of the liquid in one of said chambers falls below a predetermined value.

12. In apparatus for cooling a liquid, the combination of a receptable, a partition in said receptacle for dividing the latter into a plurality of evaporating chambers, means for 'causing the liquid to flow through said chambers in succession, a plurality of steam ejectors communicating with one of said chambers, said partition being formed with an opening, whereby a partial evaporation of the liquid is effected in each of said chambers by said ejectors and means responsive to the temperature of the liquid in one of said chambers for rendering one of said ejectors inoperative when the temperature of said liquid falls below a predetermined value.

13. In apparatus for cooling a liquid, the combination of a receptacle, a partition in said receptacle for dividing the latter into a. plurality of evaporating chambers, means for causing the liquid to flow through said chambers in succession, a plurality of steam ejectors communicating with one of said chambers, said partition being formed with an opening whereby a partial'evaporation of the liquid is effected in each of said chambers by said ejectors and means for rendering one of said ejectors inoperative when the temperature of the liquid in one of said chambers falls below a predetermined value.

14. In apparatus for cooling a liquid, the combination of a receptacle, partitions in said receptacle for dividing the latter into a plurality of evaporating chambers, means for causing the liquid to fiow through said chambers in succession, exhausting means communicating with one of saidchambers, said partitions being formed with openings which progressively increase in size, whereby a partial evaporation of the liquid is eflected in each of said chambers and its temperature is progressively lowered.

15. In apparatus for cooling a liquid, the combination of a receptacle, partitions in said receptacle for dividing the latter into a plurality of evaporating chambers, means for causing the liquid to flow through said chambers in succession, exhausting means communicating with one of said chambers, said partitions being formed with openings which progressively increase in size, whereby a partial evaporation of the liquid is efiected in each of said chambers and its temperature is progressively lowered and means for regulating said exhausting means in accordance with the temperature of the q d.

16. In apparatus for cooling at liquid, the combination of a receptacle, partitions in said receptacle for dividing the latter into a plurality of evaporating chambers, means for causing the liquid to flow through said chambers in succession, a plurality of ejectors communicating with one of said chambers, said partitions being-formed with openings which progressively increase in size, whereby a partial evaporation of the liquid is efiected in each of said chambers and its temperature is progressively lowered and means for controlling the operation of said ejectors in accordance with the temperature of the liquid in each of said chambers.

17. In apparatus for cooling a liquid, the combination of a plurality of evaporating chambers through which the liquid is caused to fiow, means providing paths of communication between said chambers, a plurality of steam ejectors communicating with one of said chambers whereby a partial evaporation of the liquid is effected in each of said chambers by said ejectors, means for rendering one of said ejectors inoperative when the temperature of the liquid in one of said evap-..

orating chambers falls below a predetermined value and a separate condensing chamber for each of said ejectors, whereby the emciency of the remaining ejectors is unimpaired when one of them is rendered inoperative.

18. In apparatus for cooling a liquid, the com bination of a plurality of chambers through which the liquid is caused to flow, exhausting means for evacuating said chambers so that as the liquid flows through them a partial evaporation of the .liquid is effected and the temperature of the liquid is progressively lowered and means for reducing thejate of evaporation of the liquid in said chambers when the temperature of the liquid in one of said chambers falls below a predetermined value.

19. In apparatus for cooling a liquid, the combination of a plurality of chambers through which the liquid is caused to flow, a plurality of ejectors for evacuating said chambers so that as the liquid flows through them a partial evaporation of the liquid is effected and the temperature of the liquid is progressively lowered and means for rendering one of said ejectors inoperative when the temperature of the liquid in one of said chambers falls below a predetermined value.

' HAROLD M. GRAHAM. 

